in hugegraph-common/src/main/java/org/apache/hugegraph/concurrent/KeyLock.java [110:131]
public List<Lock> lockAll(Object key1, Object key2) {
E.checkArgument(key1 != null, "Lock key can't be null");
E.checkArgument(key2 != null, "Lock key can't be null");
Lock lock1 = this.locks.get(key1);
Lock lock2 = this.locks.get(key2);
int diff = lock1.hashCode() - lock2.hashCode();
if (diff == 0 && lock1 != lock2) {
diff = this.indexOf(lock1) - this.indexOf(lock2);
assert diff != 0;
}
List<Lock> locks = diff > 0 ?
ImmutableList.of(lock2, lock1) :
ImmutableList.of(lock1, lock2);
for (Lock lock : locks) {
lock.lock();
}
return locks;
}